Measured service telephone system



Oct. 8, 1940. H. P. BoswAU MEASUEED SERVICE TELEPHONE SYSTM Filed- Dec.24, 193s Patented Oct. 8, 1940 UNITED STATES PA'rlszN'rA OFFICEMEASURE!) SERVICE TELEPHONE SYSTEM Application December 24, 1938, SerialNo. 247,618

20 Claims.

The present invention relates in general to measured service telephonesystems, and more particularly to improved circuits for use inconnection with paystation calls.

The principal object of the invention is to provide novel circuitarrangements for generating and transmitting a paystaton tone toindicate that the calling party is a paystation subscriber. Thepaystation subscribers are equipped with the socalled post-pay stationswhich require the deposit of a coin when the called party answers inorder to permit the calling party to talk to the called party. Apost-pay station of this type is shown and described in the Riebe PatentNo.

i 1,844,684, issued February 9, 1932. When a paystation subscriber callsa local line the tone is transmitted to both the calling and calledsubscribers when the called subscriber answers. This tone informs thecalled local subscriber that a paystation is calling and that he shouldwait long enough to allow the calling subscriber to deposit a coin. Thetone informs the calling subscriber that the called party has answeredand that he should deposit a coin. When a paystation subscriberoriginates a long distance call, which must be completed by an operatorin a distant exchange, the tone is started in response to the ,operatoranswering to inform the operator that a paystation subscriber is callingso that the proper fees may be collected.

Ordinarily this new and novel tone generating and transmitting circuitis connected to the paystation lines at the local exchange between theline and its individual line switch. However, this circuit is such thatit can be installed in the bell box at the subscribers residence sinceit is operated over the line conductors and does not require anyadditional battery connections. It is therefore possible to group bothregular (non-pay) and paystation subscribers on the same party line anda tone will only be generated and transmitted when a paystation line iscalling.

In the accompanying drawing are shown only such circuits of a localautomatic telephone system and a distant manual exchange as areconsidered necessary to clearly'illustrate the invention.

In Fig. l the substation A is provided with the usual receiver,transmitter, switchhook, induction coil, bell, calling device,substation circuit, and coin collect mechanism as shown and described inthe Riebe Patent No. 1,844,684. The line switches and switching throughconnector are somewhat similar to the line switch and connector shown inFig. 9 of the Saunders Patent N0. 1,805,725, issued May 19, 1931. Theline switches are the well known plunger type, and the connector is ofthe well known Strowger vertical and rotary type. In the connector onlyvthe normal post springs 933 and switch-through relay 92 I theback-bridge and line relays, 922 and 923, are shown. y

The repeater diagrammatically shown terminates the incoming trunkconductors 43 and 44 eX- tending from the distant exchange and isaccessible from the switch-through levels of the connectors. Repeatersof this type are well known and therefore only the circuits necessary todescribe and understand the invention are shown.

The trunk conductors 43 and 44 extend to the distant exchange to thewell-known ring-up and cut-off interlocking relays and jack J. The cordcircuit may be any wellknown type of cord circuit Which closes a bridgeacross the tip and ring conductors of the trunk line to answer ororiginate trunk calls.

Fig. 2 shows a slight modification of the tone generating andtransmitting device shown in Fig. 1.

Fig. 3 diagrammatically shows a party line wherein only one of thesubscribers, subscriber D, is a paystation subscriber, the remainingsubscribers on this line being regular or non-pay sub'- scribers. Thetone generating and transmitting device is shown mounted in the bell box9D indicated by the dotted rectangle.

A general description of the apparatus having been given, a detaildescription of its operation will now be proceeded with. For thispurpose it will be assumed that the paystation subscriber A desires toconverse with subscriber B.

When the receiver is removed at substation A a bridge is closed acrossthe line conductors I and 2 to cause the operation of the lineswitch inthe well-known manner. This circuit may be traced from ground at theline switch, main distributing frame jumper 6, Vthrough resistance R andthe lower dry disc rectifier I2 in parallel, jumper 4, line conductor 2,substation A, line conductor I, main distributing frame jumpers 3 and 5to the line relay and battery in the line switch. Assuming that theconnector shown is the connector seized by the operation of the lineswitch, then the battery and ground connections through line relay 923is substituted for the battery and ground at the line switch. Thecircuit for line relay 923 extends over the previously tracedsubscribers loop by way of contacts I5 and I6, back 'contacts I1 and I8and through the normally closed springs controlled by contacts I9 and 20to the winding of the line relay.

Subscriber A now dials the digits corresponding to the telephone numberof substation B to cause the connector wipers 25 and 26 to engage bankcontacts 29 and 39 of the called line and to ring the called party inthe well known manner or as described in the Saunders Patent No.1,805,726. Contacts 23 and 24 were closed during the operation of theconnector and when subscriber B answers the ring-cut-oi relay operatesto disconnect ringing current and complete the circuit for back bridgerelay 922 at contacts 2| and 22 over the called subscribers loop. Backbridge relay 922, upon operating, at contacts I9 and reverses batteryback over the calling subscribers loop. This reversal of battery nowcauses the operation of relay III over a circuit including dry discrectier I I and the lower winding of relay I0. Relay Il) operates itsarmature contact 'I causing it to` strike contact spring 9 to which aweight 8 is attached. Due to this striking action, weight 8 and spring 9are vibrated for a predetermined time and during this vibration contacts'I and 9 are intermittently closed and opened to produce a tone which isaudible to both calling and called subscribers. Eventually, thevibrating contact 9 comes to rest in engagement with contact 'I, therebystopping the tone and continuously connecting the upper non-inductivewinding of relay I0 in the loop circuit in parallel with resistance R toreduce the total series resistance therein. The called party is informedby the audible tone that a paystation subscriber is calling him and thathe should wait a sufficient length of time to allow the callingsubscriber to deposit the required coin. The calling party is informedby the audible tone that the called party has answered and he mustdeposit a coin before he can talk to the called subscriber as describedin the Riebe Patent No. 1,844,684.

After conversation and in response to either subscriber replacing hisreceiver relay I0 restores. In case the calling subscriber hangs up rstthen the circuit through the lower winding of relay I0 is opened, and incase the called subscriber hangs up iirst the back bridge relay 922restores and reverses the battery connections to normal in which casethe dry disc rectier II blocks the passage of current through the lowerwinding of relay ID.

On local calls to the paystation the current over the called lineconductors is not reversed and therefore relay I0 does not operate. Theresistance R connected in shunt of the lower winding of relay I0 issuiciently low to prevent operation of relay I0 by ringing current, partof which ows through rectifier II and the lower relay winding.

Having described the operation which takes place when a paystationsubscriber calls another local subscriber, a description will now begiven of a call in which the paystation subscriber desires to make along distance call which must be completed by a manual operator in thedistant exchange.

Assuming now that subscriber A desires to make a long distance call andin response to the removal of the receiver the line switch has operatedand seized the switch through connector as previously described. Callingsubscriber A now dials the digits necessary to trunk the call to thedistant exchange and in response to dialling the first digit theconnector wipers are positioned opposite the trunk level and the normalpost` springs 933 are operated. The second digit rotates the connectorwipers to the desired group after which the connector hunts for an idletrunk extending to the distant exchange. Assu-me now that the connectorseizes, over bank contacts 21 and 29, the repeater shown terminating therst idle trunk line. In response to this seizure switch-through relay92I is operated to substitute battery and ground through the winding ofthe repeater line relay 49 for the connector line relay 923. Thiscircuit extends from battery and ground through the windings of linerelay 40, normally closed springs controlled by contacts 31 and 38,conductors 35 and 36, bank contacts 2'I and 28, wipers and 26, frontcontacts II and I8 of switch-through relay 92|, and thence over thecalling subscribers loop.

In response to the operation of line relay 40 in the repeater, a relayoperation (not shown) takes place to operate contacts 43 and 44 to causea splash of ringing current to be transmitted over the trunk conductors45 and 46 to the distant exchange after which contacts 4I and 42 areoperated to disconnect the ringing current and prepare the circuit forreversing relay 39.

In the distant exchange, ring-up relay 53 is operated by the momentarysplash of ringing current and mechanically locks up. The ring-up relay53 and cut-olf relay 54 are interlocking and are well known, having beenusedextensively in manual telephone systems. At contact 5I ringup relay53 lights the call lamp L to signal the distant exchange operatorwhereupon the operator inserts the plug of her cord circuit into jack Jand throws her answer key K. Cut-01T relay 54 is operated over thesleeve of the jack through resistance Sil to battery, thereby connectingthe bridge 6I in the cord circuit across the trunk conductors 45 and 46to operate reversing relay 39. Relay 39 is operated over the followingcircuit: ground and battery through both windings of relay 39, frontcontacts 4I and 42, trunk conductors 4-5 and 46, front contacts 5I and52, tip and ring of jack J, tip and ring of the plug of the operatorscord circuit and through the bridge 6I.

Reversing relay 39, upon operating, at contacts 3l and 38 reversesbattery back over conductors 35 and 33, wipers 25 and 26, front contactsI'I and I8, and thence over the subscribers loop. Dry disc rectifier I Ipermits current to flow in the lower winding of relay I0 and due to thisreversal of current relay I0 is operated as previously described. Thetone generated by the vibration of spring 9 and weight 8 is audible toboth the calling subscriber and the operator at the distant exchange. Onreceipt of this tone the operator at the distant exchange is advisedthat the calling party is at a paystation and that the proper feesshould be collected for the connection when completed. The operator atany time can check the call and restart the tone by simply removing andreplacing her plug to cause the restoration and reoperation of reversingrelay 39 which will release and reoperate tone relay I0 as previouslydescribed.

Fig. 2 shows a slight modification over the tone relay circuit shown inFig. 1. The only difference being that the lower dry disc rectifier,such as rectifier I2, has been omitted from Fig 2. This circuit resultsin only a slightly higher transmission loss on paystation calls andwould not be objectionable on certain lines.

The paystation tone relay circuit shown in Fig. 3 shows a somewhatsimilar circuit to the one in Fig. l except that a condenser C is usedin place of resistance R. This circuit provides more operating currentfor the relay 8 and is, therefore, suitable for long subscribers loops.In order to keep the total series resistance sufficiently low, theresistance of the upper non-inductive winding of relay 80 is reducedfrom that shown in Fig. 1 so that the relay will hold up with thisreduced shunt, inasmuch as the resistance R of Fig. 1 is replaced bycondenser C'.

One of the features of the invention is shown in Fig. 3 wherein the tonerelay 80 is mounted in the bell box at the subscribers residence. Fig. 3represents a party line in which only one of the parties, or party D, isa paystation and all of the remaining parties C, E and F are regular ornonpay party line subscribers. Since this tone relay is operated overthe two line conductors and does not need any additional sourceofbattery or connections it is possible to provide one or morepaystations on any party line. In the example shown in Fig. 3 tone relayBil is only operated by reversal of current when subscriber D initiatesa call, since the relay is only cut into the line circuit when thereceiver is removed at substation D. Since it is obvious how relay 80 isoperated in view of the foregoing description, its detail operation willnot be described.

Having described the invention and what is considered new and desired tobe protected by Letters Patent is set forth in the following claims.

What is claimed is:

1. In a telephone system, a calling and a called subscribers lineterminating in a local exchange, means at the exchange for establishinga connection between said lines, a tone generating device located atsaid exchange individual to the calling line, and means for operatingsaid device upon the response of the called line to transmit an audibletone to both the calling and called subscribers.

2. In a telephone system, a calling and a called subscribers lineterminating in a local exchange, means at the exchange for establishinga connection between said lines, a tone generating device individual toeach said line and located in said local exchange, and means foroperating only the tone generating device individual to the calling linein response to the called line answering the call to transmit a tone toboth the calling and called subscribers.

3. In a telephone system, a calling and a called line terminating in alocal exchange, means at said exchange for establishing a connectionbetween said lines, a tone generating device individual to the callingline and located at the local exchange, means responsive to the calledsubscriber answering for reversing battery back over said connection,and said tone generating device operated in response to said reversalfor transmitting a tone to both the calling and called subscribers.

4. In a telephone system, a party line, paystations and regular non-paysubstations on said party line, a tone generating device connected tosaid party line at each paystation, a called subscribers line, means forestablishing a connection between a calling paystation on said partyline and said called line, and means responsive to the called subscriberanswering for operating the calling paystations tone generating deviceto transmit a tone to both the calling and called parties.

5. In a telephone system, a party line, paystations on said party line,a tone generating device at each paystation, a called subscribers' line,means for establishing a connection between a calling paystation on saidparty line and said called line, and means responsive to the calledsubscriber answering for operating the calling paystations tonegenerating device to transmit a tone to both the calling and calledparties, said tone generating devices at each paystation being normallyinoperative and become effective for operation only in response to acall from the corresponding paystation,

6. In a telephone system, a party line, paystations and regular non-paytelephones on said party line, a tone generating device individual toeach paystation on said party line, a called subscribers line, means forestablishing a connection between a calling party on said party line andsaid called line, and means responsive to the called subscriberanswering for operating an individual tone generating device to transmita tone to both the calling and called subscribers only in case the calloriginated from a paystation on said party line.

'7. In a telephone system, a party line, a plurality of subscriberssubstations on said party line, some of said substations on said partyline being of a different character than the remaining substations onsaid line, a tone generating device individual to each of said somesubstations of a different character, a called subscribers line, meansfor establishing a connection between said party line and said calledline, and means responsive to the called subscriber answering foroperating an individual tone generating device to transmit a tone toboth the calling and called subscribers only in case a substation ofsaid different character originated the call.

8. In a telephone system, a local exchange, a calling line terminatingin said local exchange, a distant exchange, an operators position in thedistant exchange, a trunk line interconnecting said exchanges andterminating in said operators position, means for establishing aconnection between said line and said operators position over said trunkline, a tone generating device individual to said calling line andlocated in said local exchange, and means in said trunk line foroperating said tone generating device in response to the operatoranswering the establishment of said .connection to transmit a tone tothe operator over said trunk line.

9. In a telephone system, a local exchange, a party line terminating insaid local exchange, paystations and regular non-pay substations on saidparty line, a distant exchange, an operators position in said distantexchange, a trunk line interconnecting said exchanges and terminating insaid operators position at the distant exchange, means for establishinga connection'between said line and said operators position over saidtrunk line, a tone generating device individual to each paystation onsaid party line, and means responsive to the operator answering theestablishment of said connection for operating a tone generating deviceonly in case a paystation on said party line originated the call.

10. In a telephone system, a plurality of party i lines, paystations andregular non-pay substations on each of said party lines, a tonegenerating device at each paystation, means for establishing aconnection between a calling party on one party line and a called partyon anothery party line, said tone generating devices at each paystationbeing normally inoperative, means at each paystation for rendering itstone generating device effective for operation only when the receiver isremoved from such paystation, and f means responsive to the called partyanswering for operating only the .calling partys tone generating device.

1l. In a telephone system, a local exchange, a

calling line terminating in said local exchange, i'

a distant exchange, an operators position in the distant exchange, arepeater in the local exchange, a trunk line interconnecting Saidexchanges terminating in said repeater at the local exchange and in saidoperators position at the distant exchange, means including `automaticvswitches for establishing a local connection between said calling lineand other local lines terminating in said local exchange, meansincluding said automatic switches, said repeater, and said trunk linefor establishing a trunk connection between said calling line and saidoperators position, a tone generating device individual to said Acallingline operative to transmit a tone to both the calling and called partieson local connections and to both the calling party and the operator ontrunk connections, means in one of said automatic switches for operatingsaid device on local connections when the called local subscriberanswers, said last means ineffective von trunk connections, and means insaid repeater .for operating said device on trunk connections yWhen theoperator answers.

- l2. In a telephone system, a telephone line, a

vpaystatio-n on said line, a relay and a rectifier individual to saidpaystation and connected to said line, means including said rectifierfor operating vor preventing the operation of said relay dependent uponthe direction of flow of current over said line, and a tone producingcircuit individual to said paystation and connected to said line fortransmitting a tone over said line indicatve of said paystation inresponse to the operation of said relay when current i'iows over said,line in the proper direction to operate said relay.

13. In a tone generating device for a paystation telephone subscribersline, a relay, an operating winding of said vrelay and a rectifier inseries connectedto said line, means including Asaid rectiiier foroperating or for preventing the operation of said relay dependent uponthe direction of current flow over said line, a tone producing circuitincluding vibratory springs on said relay connected to said line fortransmitting a tone over said line indicative of said paystation,

and means for operating said relay in response to the properdirection ofcurrent flow over said -line to vibrate said springs'thereby causingsaid tone producing circuit to generate said tone.

14. In a paystation substation comprising a paystation circuit and atone generating device, said tone generating device comprising a relayvand a rectifier connected to said substation telephone circuit, saidrectifier rendering said relay inoperative when current flows over saidsubstation-telephone circuit in one direction but operative When4current ows in the opposite direction, and a tone producing circuit insaid device controlled by the operation of said relay when operated bycur'rent flow over said substation circuit in'said opposite directionfor transmitting a tone indicative of a paystation substation.

15. In a telephone system, an exchange, a line terminating in saidexchange, a paystation subscriber on said line, a tone generating deviceindividual to said line, a relay and a rectifier included in said deviceand connected to said line, means including said rectier for renderingsaid relay inoperative when current flows over said line in onedirection but operative when current .flows over said line in theopposite direction, and .a tone producing circuit included in saiddevice and connected to said line for transmitting a tone over said lineindicative of a paystation substation when said relay is operated bycurrent iiow over said line in said opposite direction.

16. In a paystation substation comprising a paystation telephone circuitand a tone generating device, said tone generating device normallyinoperative when current iiows over said substation circuit in onedirection, and means for operating said tone generating device for onlya predetermined time in response to current flow over said substationcircuit in the opposite direction to transmit a tone indicative of apaystation substation.

1'7. In a tone generating device, a relay, an operating circuit for saidrelay, a rectier and an operating winding of said relay included in saidoperating circuit, said rectifier blocking current ow over saidoperating circuit when current flows in one direction, a resistanceconnected in shunt of said operating circuit for partially restrictingcurrent flow in either direction over said operating circuit, means foroperating said relay over said operating circuit when current flows inthe opposite direction, a vibratory spring operated for a predetermined.time in response to said relay operation, and a second circuitintermittently closed and opened by said vibrating spring for generatinga tone, said second circuit including said springs and a second windingof said relay connected in shunt of said operating circuit.

18. In a tone generating device, a relay, an`

operating circuit for said relay, a rectier and an operating Winding ofsaid relay included in said operating circuit, a second rectifierconnected in shunt of said operating winding for bypassing current flowover said operating circuit when such current flows in one direction, animpedance connected in shunt of said operating circuit for partiallyrestricting the current flow in said operating circuit, means foroperating said relay over said operating circuit when the current ows inthe opposite direction, and a second circuit intermittently closed andopened for a predetermined time in response to said relay operation forgenerating a tone, said second circuit including a second winding ofsaid relay connected in shunt of said operating circuit.

19. In a tone generating device, a relay, an operating circuit for saidrelay, a rectifier and an operating winding of said relay included insaid operating circuit, said rectifier blocking current flow over saidoperating circuit when current flows in one direction, means foroperating said relay over said operating circuit when current iiows inthe opposite direction, and a tone producing circuit controlled by theoperation of said relay for generating a tone 20. In a telephone system,a subscribers line terminating in an exchange, a tone generating deviceindividual to said line, a relay in said device, an operating circuitfor said relay connected to said line, a rectifier and an operatingwinding of said relay included in said operating circuit, said rectierblocking current flow over said operating circuit when current iiows inone direction over said line, means for operating said relay over saidoperating circuit when current flows in the opposite direction over saidline, a tone producing circuit controlled by the operation of said relayfor transmitting a tone over said line, and means controlled by theoperation of said relay after a predetermined time for reducing thetotal line resistance in said subscribers line loop extending to saidexchange.

l HANS P. BOSWAU.

